Is there a way to make a bash alias (or function) with its name coming from a variable?
For instance, is it possible to do something along these lines:
create_alias_with_name() {
alias $1="echo a custom alias"
}
Or something along these lines:
create_func_with_name() {
$1() {
"echo inside a function with a variable name"
}
}
In other words, I would prefer to have some kind of function "factory" that can register functions for me. Is this possible or beyond the capabilities of Bash?
Did you even try it? Your first example works fine.
You can make the second work by adding an eval:
create_func_with_name() {
eval "$1() {
echo inside a function with a variable name
}"
}
just in case, one may use a variable both as a part of the alias name and as a part of the alias command:
alias foo${var1}="bar${var2}"
Related
I have a script with many other scripts sourced. Each script sourced have a function.
One of my function need to stop according to a if statement. I tried continue, break, throw, evrything I saw on internet but either my main script completely end or my function continue.
Function code:
function AutoIndus-DeployUser($path){
$yaml=Get-Content $path | ?{!$_.StartsWith("#")}
$UsersPwd=$false
$user="";$password="";$groups="";$description=""; $options=""
$yaml | %{
if (($_-match "}") -and ($UsersPwd -eq $true)){Write-Host "function should stop"; return}
*actions*
}
}
Main script:
#functions list and link to extern scripts
Get-ChildItem -Path $PSScriptRoot\functions\ | %{$script=$_.Name; . $PSScriptRoot\functions\$script}
myfunction-doesnotwork
*some code*
Edit: I saw that return should stop the function without stoping the rest of the script, unfortunatly it does not stop anything at all:
Output:
Config file found
---
Changing user _usr-dba password
Changing user _usr-dba2 password
function should stop
Changing user _usr-dba3 password
function should stop
function should stop
function should stop
function should stop
function should stop
Disabling user DisableAccounts:{
Disable-LocalUser : User DisableAccounts:{ was not found.
At C:\Scripts\AWL-MS-AUTOMATION_AND_TOOLS\functions\AutoIndus-DisableAccount.ps1:25 char:13
+ Disable-LocalUser -Name $disable
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (DisableAccounts:{:String) [Disable-LocalUser], UserNotFoundException
+ FullyQualifiedErrorId : UserNotFound,Microsoft.PowerShell.Commands.DisableLocalUserCommand
Disabling user _usr-dba
To help you understanding, my script read a file and do actions according to each line it is reading. It start acting when it encounter something like User{ and should stop when it encounter }, _usr-dba3 being out of the curvy brackets it should not be treated. This way all my other function use the same one file. (changing user password and diasabling user are two different functions/sourced scripts)
Like you can see return does not do its job, maybe I'm missing one point in the use of return but I don't get it right now.
To prematurely exit out of a function before you reach the end of it, use
return
it works like break to where it will stop execution but instead of stopping the whole thread it will return back to the line below where you called the function.
Also keep in mind if your function has an output set return will return it back, for example with the function below:
function Get-ReturnValue()
{
$returnValue = "this is my output"
return $returnValue
}
if you called it like this:
$receivedReturnValue = Get-ReturnValue
then the variable receivedReturnValue would be loaded with the output of the function.
I needed a fast solution so I changed my functions, now there is no return/continue/... but a value that turn true. It is initialized to false and the action on each yaml lines are done when the value is equal to false.
Edit: So finally the issue was I didn't used function correctly. Return only works if you return into another function. So I putted almost the entire sctipt into a function that calls the function AutoIndus-DeployUser. Now it works perfectly !
I want to make use of functions to get the full path and directory name of a script.
For this I made two functions :
function _jb-get-script-path ()
{
#returns full path to current working directory
# + path to the script + name of the script file
return $PWD/${0#./*}
}
function _jb-get-script-dirname ()
{
return ${(_jb-get-script-path)##*/}
}
as $(_jb-get-script-path) should be replaced by the result of the function called.
However, I get an error: ${(_jb-get-script-path)##*/}: bad substitution
therefore i tried another way :
function _jb-get-script-path ()
{
return $PWD/${0#./*}
}
function _jb-get-script-dirname ()
{
local temp=$(_jb-get-script-path);
return ${temp##*/}
}
but in this case, the first functions causes an error : numeric argument required. I tried to run local temp=$(_jb-get-script-path $0) in case the $0 wasn't provided through function call (or i don't really know why) but it didn't change anything
I don't want to copy the content of the second fonction as i don't want to replicate code for no good reason.
If you know why those errors happen, I really would like to know why, and of course, if you have a better solution, i'd gladely hear it. But I'm really interessed in the resolution of this problem.
You need to use echo instead of return which is used for returning a numeric status:
_jb-get-script-path() {
#returns full path to current working directory
# + path to the script + name of the script file
echo "$PWD/${0#./*}"
}
_jb-get-script-dirname() {
local p="$(_jb-get-script-path)"
echo "${p##*/}"
}
_jb-get-script-dirname
I'm trying to store a value returned from a method like this: var=$(methodName), but the program never enters the method... It's weird because I do the same thing a few lines earlier (alreadyExists-variable in code sample), and it works fine. I had to do this: var='methodName' to make the program enter the method.
It works, so why care? I'm probably making a mistake, and I need to know what it is and learn from it. Let me know if you need more info to answer the question. Thanks!
overwriteOrNot()
{
echo DEBUG
# This debug string does not print if method is called from "local overwrite=$(overwriteOrNot)"
# but prints if method is called from "local overwrite='overwriteOrNot'"
...
}
local alreadyExists=$(studentNumberExists studentNumber)
if $alreadyExists ; then
# local overwrite=$(overwriteOrNot)
local overwrite='overwriteOrNot'
...
If you're using return, then you need to either directly branch on its result:
if overwriteOrNot; then
: "the function returned 0"
else
: "the function returned something other than 0"
fi
...or store the value of $? immediately after running the function:
overwriteOrNot
local overwrite=$?
Note that return can only return a single-byte integer. If you need to pass content which doesn't fit that type, it needs to be either passed on stdout or in a global variable.
The following:
local overwrite='overwriteOrNot'
assigns a string; it doesn't invoke a function. Instead:
local overwrite=$(overwriteOrNot)
You can check the return value from calling overwriteOrNot with the $? variable, or by checking its numeric return value directly in a conditional statement like:
if overwriteOrNot; then
:
fi
If you assign to overwrite, you can also check its value with any valid test condition such as equality, regular expression match, or emptiness. For example:
if [[ "$overwrite" == "foo" ]]; then
:
fi
I'm using Oh My Zsh on OS X. I'm trying to write an autocomplete function that outputs my combined tmux and tmuxinator sessions.
Here's what my autocomplete function looks like:
tmux-and-tmuxinator-sessions-autofill() {
reply=$( tmux-and-tmuxinator-sessions )
}
compctl -K tmux-and-tmuxinator-sessions-autofill ta
tmux-and-tmuxinator-sessions outputs the following:
dotfiles
landonschropp.com
something
something_else
However, If I type ta and hit tab, I get:
ta dotfiles$'\n'landonschropp.com$'\n'something$'\n'something_else
I'm pretty new to Zsh, so any help would be appreciated.
reply should be an array, not a single string.
tmux-and-tmuxinator-sessions-autofill() {
reply=( $(tmux-and-tmuxinator-sessions) )
}
I'm not really sure a good name for this question so please rename it if you can think of a better one.
In Bash I have a function that I am using to store certain functions. Consider:
menv_funcs=()
function menv_function {
menv_funcs+=($1)
}
I am then using it in this manner:
menv_function fetch
function fetch {
...
}
I would like to use it like this though:
menv_function fetch {
...
}
Essentially I'm looking for something like the preprocessor macros in C would do but I have been unable to find a way. Any ideas?
As far as I'm aware, you can't directly achieve this. However, I can think of two solutions that may be of interest to you.
First of all, you could just declare the functions as usual, and then obtain the list of declared functions through declare -F. This could be done like:
function fetch {
:
}
menv_funcs=()
while IFS=$"\n" read l; do
menv_funcs+=${l#declare -f }
done < <(declare -F)
Which will cause menv_funcs[#] to list all the functions declared at the point of calling the snippet. Of course, this may catch unwanted functions as well.
To avoid this, you may add some prefix to function names and filter the list:
function menv_fetch {
:
}
menv_funcs=()
while IFS=$"\n" read l; do
if [[ ${l} == 'declare -f menv_'* ]]; then
menv_funcs+=${l#declare -f menv_}
fi
done < <(declare -F)
And if you really want to achieve something like macros, you may try to play with eval:
menv_funcs=()
function menv_function {
local name=${1}
local body=${2}
menv_funcs+=( ${name} )
eval "function ${name} ${body}"
}
menv_function fetch "{
:
}"
But note that you will actually need to quote the whole function body and escape everything appropriately.